多相物质的有效导热系数
来源期刊:中南大学学报(自然科学版)1999年第2期
论文作者:周孑民 李长庚 刘健君
文章页码:104 - 107
关键词:多相充填床;数学模型;数值计算;相变;有效导热系数
Key words:multiphase packed bed;mathematical model;mathematical simulation;phase;effective thermal conductivity
摘 要:对由固体球状颗粒和经历了相变的充填 物所组成的多相充填床建立了数学模型,对充填物的熔化和凝固过程进行了数值计算,并在此基础上计算了由不同相所组成的区域内的有效导热系数.运用特殊的数学方法处理相变过程中潜热的释放或吸收,分析了导热参数的变化对有效导热系数的影响.得出有效导热系数的计算结果:对于玻璃球 冰充填床,为1.56W/(m·K),和实验结果的相对误差为2.5%;对玻璃球 水充填床,为0.78W/(m·K),和实验结果的相对误差为3.8%.这表明:用数值计算的方法研究多相物质的有效导热系数是一种行之有效的手段。
Abstract: A mathematical model has been developed for a multiphase packed bed which consists of sphercal particles and surrounding material undergoing phase ttransformation.the model has been applied to mathematical simulation of the melting and freezing processes of surrounding material.Effective thermal conductivities in zones which consist fo different phase have been calculated on the basis of the simulation.A special mathematical method is applied to the phase transition to treat the latentheat release or absorption.Variations of parameters affecting the heat transfer process as well as the effecvive themal conductivity have been analyzed.the effective thmal conductiveity of glass sphere ice packed bed obtained from computer simulation os 1.56W/(m·K) and the relative difference is 3.8%.These results prove that the method of computer simulation is an effective way to investigate into the effective themal conductivity of multiphas material.